Answers

2015-06-07T14:36:18+08:00
Infinite set:
{0,1,2,3,4,5,6,7,8,9,10,11,12,13.....................}
ЕmEn {m and n are integers and x = m/n}
A x {x ∈ S1 ⇔ x ∈ s2} ⇒ S1 = S2
Empty set:
{ } or Ф
1 5 1